JP2021063014A - Leukemia therapeutic agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new means for treating leukemia beyond tyrosine kinase inhibitor therapy. A leukemia therapeutic agent comprising a combination of an immune checkpoint inhibitor and a tyrosine kinase inhibitor. [Selection diagram] None

Description

The present invention relates to a novel therapeutic agent for leukemia.

Leukemia is a disease in which blood cells become cancerous in the process of being made in the bone marrow. Normal blood cells are reduced, and symptoms such as anemia, decreased immune system function, bleeding tendency, and enlarged spleen appear. Leukemia is classified into acute myeloid leukemia (AML), chronic myelodysplastic leukemia (CML), and acute lymphocytic leukemia (ALL), depending on the type of cancerous cells and the pattern and symptoms of disease progression. : Acute lymphoblastic leukemia), chronic lymphocytic leukemia (CLL), myelodysplastic syndrome (MDS) and the like.

Leukemia is generally thought to be caused by mutations in genes and chromosomes. For example, chronic myelogenous leukemia (CML) is a reciprocal translocation of chromosomes 9 and 22 t (9:22) (q34: q11). ) Is characterized by a Philadelphia (Ph) chromosome formed by. The constitutive activation of the BCR-ABL tyrosine kinase encoded by the BCR-ABL fusion gene generated on the Ph chromosome causes tumorigenesis of hematopoietic stem cells.
Treatments for leukemia include hematopoietic stem cell transplantation, molecular-targeted therapies, chemotherapy, and interferon alpha therapy. As mentioned above, since leukemia is caused by activation of tyrosine kinase by mutation of genes and chromosomes, the development of molecular-targeted drugs that inhibit tyrosine kinase has brought about a revolutionary improvement in the therapeutic results of leukemia (non-). Patent Document 1).

Niigata Cancer Center Hospital Medical Journal Vol. 51, No. 1, pp. 7-12 (March 2012)

However, the presence of patients who are resistant to tyrosine kinase inhibitors, the problem of discontinuing tyrosine kinase inhibitors, and the recurrence due to the acquisition of tyrosine kinase resistance mutations still remain as problems.
Therefore, an object of the present invention is to provide a new therapeutic means for leukemia that goes beyond tyrosine kinase inhibitor therapy.

Therefore, the present inventor has investigated various causes of tyrosine kinase inhibitor resistance, and the cause of recurrence is the residual leukemic stem cells that are drug-resistant, and the leukemic stem cells maintain the stem cell nature of hematopoietic stem cells. It was considered that one of the reasons for showing drug resistance is that it has become cancerous and its cell cycle is in a dormant state (G0 phase). A chronic myelogenous leukemia (CML) -like model using mice introduced with a G0 marker (Oki et al., Sci Rep, 4,4012 (2014)) that can visualize G0 phase cells developed by the present inventor. Mice were constructed and studied to clarify the relationship between G0 phase of CML stem cells and drug resistance. That is, imatinib, which is a tyrosine kinase inhibitor, is administered to CML-like model mice into which the BCR-ABL gene and the G0 marker have been introduced to obtain an imatinib-resistant CML stem cell fraction, which is further divided by the expression of the G0 marker and CD27. Therefore, it was found that imatinib-resistant CML stem cells were concentrated in the G0 marker ⁺ / CD27 ⁺ fraction, and PD-L1 was further expressed in the imatinib-resistant CML stem cell fraction in the bone marrow and spleen after the onset of CML. It was confirmed. Therefore, when a tyrosine kinase inhibitor and an immune checkpoint inhibitor were co-administered to CML model mice, it was found that the survival time of CML mice was significantly prolonged as compared with the case where each of these drugs was administered alone. It was. We also found that the combined administration of a tyrosine kinase inhibitor and an immune checkpoint inhibitor significantly reduced the number of CML stem / progenitor cells (G0 phase leukemia stem cells) in the bone marrow, and completed the present invention.

That is, the present invention provides the following inventions [1] to [11].
[1] A leukemia therapeutic agent obtained by combining an immune checkpoint inhibitor and a tyrosine kinase inhibitor.
[2] The leukemia therapeutic agent according to [1], wherein the leukemia therapeutic agent is a leukemia therapeutic agent that reduces G0 phase leukemia stem cells.
[3] The leukemia therapeutic agent according to [1] or [2], wherein the immune checkpoint inhibitor is an anti-PD-L1 antibody, an anti-PD-1 antibody, or an anti-CTLA-4 antibody.
[4] Tyrosine kinase inhibitors are imatinib, nilotinib, ibrutinib, ponatinib, bostinib, dasatinib, osimertinib, axitinib, bandetanib, basopanib, gefitinib, dacomitinib, nintedanib, kizailtinib , And the leukemia therapeutic agent according to any one of [1] to [3], which is a component selected from salts thereof.
[5] The leukemia therapeutic agent according to any one of [1] to [4], which is a leukemia therapeutic agent composition containing an immune checkpoint inhibitor and a tyrosine kinase inhibitor.
[6] A combination of an immune checkpoint inhibitor and a tyrosine kinase inhibitor for the production of a therapeutic drug for leukemia.
[7] The combination according to [6], wherein the leukemia therapeutic agent is a leukemia therapeutic agent that reduces G0 phase leukemia stem cells.
[8] A combination of an immune checkpoint inhibitor and a tyrosine kinase inhibitor used for the treatment of leukemia.
[9] The combination according to [8], wherein the treatment of leukemia is a treatment of leukemia that reduces G0 phase leukemia stem cells.
[10] A method for treating leukemia, which comprises using an immune checkpoint inhibitor and a tyrosine kinase inhibitor in combination.
[11] The treatment method according to [10], wherein the treatment of leukemia is a treatment of leukemia that reduces G0 phase leukemia stem cells.

According to the present invention, by using an immune checkpoint inhibitor and a tyrosine kinase inhibitor in combination, GO stage leukemia stem cells can be significantly reduced, leukemia can be completely cured, and tyrosine kinase inhibitor resistant leukemia can be used. Can also be treated.

It is a figure which shows the identification method of imatinib resistant CML stem cell. It is a figure which shows that the G0 marker ⁺ / CD27 ⁺ fraction (DP) is an imatinib resistant CML stem cell. It is a figure which shows that PD-L1 is expressed in G0 marker ⁺ / CD27 ^{+ fraction (DP).} It is a figure which shows the method of the combination therapy of imatinib and anti-PD-L1 antibody for CML mouse. It is a figure which shows the result of the combination therapy of imatinib and anti-PD-L1 antibody. It is a figure which shows the change of the number of CML stem / progenitor cells in the bone marrow by the combination therapy of imatinib and anti-PD-L1 antibody.

The leukemia therapeutic agent of the present invention contains an immune checkpoint inhibitor and a tyrosine kinase inhibitor as active ingredients.

As the immune checkpoint inhibitor, known immune checkpoint inhibitors can be used, and examples thereof include anti-PD-L1 antibody, anti-PD-1 antibody, and anti-CTLA-4 antibody. Of these, anti-PD-L1 antibody and anti-PD-1 antibody are preferable, and anti-PD-L1 antibody is more preferable.
Here, examples of the anti-PD-1 antibody include nivolumab, pembrolizumab, cemiplimab, PDR001 and the like. Examples of the anti-PD-L1 antibody include avelumab, atezolizumab, and durvalumab. In addition, examples of the anti-CTLA-4 antibody include ipilimumab and tremelimumab.
These immune checkpoint inhibitors have been reported to be effective against a variety of solid tumors, but have not been shown to be effective against leukemia. Furthermore, it is completely unknown whether these immune checkpoint inhibitors have the effect of reducing G0 phase leukemic stem cells.

In the present invention, among the above-mentioned immune checkpoint inhibitors, an anti-PD-L1 antibody or an anti-PD-1 antibody is preferable from the viewpoint of a leukemia curative therapeutic effect of treating leukemia by reducing G0 stage leukemia stem cells. , Anti-PD-L1 antibody is more preferred, and avelumab, atezolizumab, and durvalumab are even more preferred.

As the tyrosine kinase inhibitor, known tyrosine kinase inhibitors can be used, for example, imatinib, nilotinib, ibrutinib, ponatinib, bostinib, dasatinib, osimertinib, axitinib, bandetanib, basopanib, gefitinib, dacomitinib, gefitinib, dacomitinib. , Legorafenib, afatinib, lapatinib, sorafenib, snitinib, erlotinib, and tyrosine kinase inhibitors selected from salts thereof.
Among these tyrosine kinase inhibitors, tyrosine kinase inhibitors selected from imatinib, nilotinib, dasatinib, ponatinib, and salts thereof from the viewpoint of leukemia curative therapeutic effect of treating leukemia by reducing G0 stage leukemia stem cells. Is more preferable.
Examples of the salt of the tyrosine kinase inhibitor include hydrochloride, malate, tosylate, maleate, mesylate, ethanesulfonate and the like. For imatinib, imatinib mesylate is preferred. For dasatinib, dasatinib hydrate is preferred. For nilotinib, nilotinib hydrochloride hydrate is preferred. For ponatinib, ponatinib hydrochloride is preferred. The tyrosine kinase inhibitor used in the present invention also includes a hydrate.

Preferred combinations of the therapeutic agents for leukemia of the present invention are (A) anti-PD-L1 antibody or anti-PD-1 antibody and (B) imatinib, nilotinib, ibrutinib, ponatinib, bostinib, dasatinib, osimertinib, axitinib, bandetanib, vasopanib, It is a combination with a tyrosine kinase inhibitor selected from gefitinib, dasatinib, nintedanib, kizyltinib, lembatinib, legorafenib, axitinib, lapatinib, sorafinib, sunitinib, erlotinib, and salts thereof.
A more preferred combination is (A) an anti-PD-L1 or anti-PD-1 antibody and (B) a tyrosine kinase inhibitor selected from imatinib, nilotinib, ponatinib, dasatinib, and salts thereof. A more preferred combination is (A) an anti-PD-L1 antibody and (B) a tyrosine kinase inhibitor selected from imatinib, nilotinib, ponatinib, dasatinib, and salts thereof.

As shown in the examples below, imatinib, which is a tyrosine kinase inhibitor, was administered to CML-like model mice into which the BCR-ABL gene and the G0 marker were introduced to obtain an imatinib-resistant CML stem cell fraction, which was referred to as the G0 marker and CD27. It was found that imatinib-resistant CML stem cells were concentrated in ^{the G0 marker +} / CD27 ⁺ fraction by further dividing according to the expression of. Furthermore, it was confirmed that PD-L1 was expressed in the imatinib-resistant CML stem cell fraction in the bone marrow and spleen after the onset of CML.
In addition, when a tyrosine kinase inhibitor and an immune checkpoint inhibitor are co-administered to CML model mice, the survival time of CML mice is remarkably prolonged as compared with the case where each of these agents is administered alone. In addition, the combined administration of a tyrosine kinase inhibitor and an immune checkpoint inhibitor significantly reduces the number of CML stem / progenitor cells (G0 phase leukemia stem cells) in the bone marrow.
Therefore, the combined use of a tyrosine kinase inhibitor and an immune checkpoint inhibitor significantly reduces tyrosine kinase inhibitor-resistant leukemia stem cells, that is, stage G0 leukemia stem cells (sleeping leukemia stem cells), resulting in a therapeutic effect on leukemia. Can be significantly improved.
The leukemia therapeutic agent of the present invention is a tyrosine kinase inhibitor-resistant leukemia in which leukemia cells in the proliferative phase are killed by treatment with a tyrosine kinase inhibitor, but dormant leukemia stem cells, that is, leukemia stem cells in the G0 phase remain. Especially useful for treatment.

The drug of the present invention may be a combination of an immune checkpoint inhibitor and a tyrosine kinase inhibitor, and two compositions containing each drug may be used in combination (combination drug), and includes two types of drugs. It may be a pharmaceutical composition. Since the immune checkpoint inhibitor and the tyrosine kinase inhibitor are already on the market, in the present invention, a form (combination drug) in which two kinds of compositions containing each drug are used in combination is preferable.

The concomitant drug or pharmaceutical composition of the present invention can be administered in any administration form, and the preparation can be selected according to the administration form. Examples of the orally administered preparation include tablets, capsules, granules, powders, syrups and the like. Examples of parenteral preparations include injections, suppositories, inhalants, transdermal absorbents, external preparations for skin, eye drops, nasal drops and the like. When an injection is selected, the route of administration includes subcutaneous injection, intramuscular injection, intraperitoneal injection, transdermal injection and intravenous injection.
The immune checkpoint inhibitor is preferably an injection. On the other hand, the tyrosine kinase inhibitor is preferably an orally administered preparation.

When preparing a solid preparation for oral use, after adding excipients, binders, disintegrants, lubricants, colorants, flavoring agents, etc. as necessary, tablets, granules, powders, etc. Capsules and the like can be manufactured.

When preparing an oral liquid preparation, an oral liquid preparation, a syrup preparation, an elixir preparation and the like can be produced by a conventional method by adding a flavoring agent, a buffering agent, a stabilizer, a preservative and the like.

When preparing an injection, a pH adjuster, a stabilizer, an isotonic agent can be added, and a subcutaneous, muscular, or intravenous injection can be produced by a conventional method.

Among the drugs of the present invention, in the case of a concomitant drug, a preparation (composition) containing an immune checkpoint inhibitor and a preparation (composition) containing a tyrosine kinase inhibitor are used in combination. When they are formulated separately in this way, they may be kit drugs in which the separately formulated drugs are combined with the instructions describing the respective administration methods. In the case of these separately formulated drugs, the dosage forms of the respective formulations may be the same or different, and the dosing intervals may be the same or different.

In the case of a pharmaceutical composition containing an immune checkpoint inhibitor and a tyrosine kinase inhibitor among the drugs of the present invention, it is preferable to contain these two drugs in one dosage form, for example, a tablet.

The usage ratio (mass ratio) of the immune checkpoint inhibitor (A) and the tyrosine kinase inhibitor (B) in the medicament of the present invention differs depending on the type of the compound used, but (A): (B) = 200. : 1 to 1: 200 is preferable, 100: 1 to 1: 100 is more preferable, and 50: 1 to 1:50 is even more preferable.

The dose of the medicament of the present invention varies depending on the compound used, the age, body weight, symptoms, etc. of the patient, but for adults, the immune checkpoint inhibitor is preferably 1 mg to 500 mg as a single dose, and 5 mg to 300 mg. Is more preferable. The daily dose of the tyrosine kinase inhibitor is preferably 1 mg to 500 mg, more preferably 5 mg to 300 mg.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
(1) A CML-like mouse was prepared by transplanting bone marrow cells derived from a G0 marker mouse into which the BCR-ABL gene was introduced into a mouse irradiated with a lethal dose by the procedure shown in FIG.
Imatinib (0.2 mg / g) was orally administered daily after the onset of CML, and imatinib-resistant CML stem cell fractions (BCR-ABL +, cKit +, Sca1 +, lineage marker negative: BCR-ABL-KSL minutes) were administered 3-4 weeks after administration. The high-purity imatinib-resistant CML stem cell fraction was identified by further dividing the image by the expression of the G0 marker and CD27.
As shown in FIG. 2, by a G0 markers and CD27, conventional CML stem cell fraction of CML mouse model ^{(BCR + KSL (ckit + Sca1} + Lineage marker -)) can be are divided into 4 fractions, in which G0 It was found that CML stem cells were concentrated in the marker ⁺ / CD27 ^{+ (double positive: DP) fraction.} That is, the survival curve in FIG. 2 is the survival curve of the mouse to which the four-divided fraction was secondarily transplanted as shown on the left of FIG. 2, and the mouse to which this DP fraction was administered had an extremely low survival rate. It was. Therefore, it can be seen that this DP fraction (G0 marker ⁺ / CD27 ⁺ fraction) is an imatinib-resistant CML stem cell fraction.

(2) Furthermore, the expression of PD-L1 in the imatinib-resistant CML stem cell fraction in the bone marrow and spleen after the onset of CML was measured. As a result, as shown in FIG. 3, it was found that PD-L1 was expressed in the ^{G0 marker +} / CD27 ^{+ (double positive: DP) fraction.}

Example 2
A combination therapy of imatinib and anti-PD-L1 antibody was performed on CML mice.
As shown in FIG. 4, after the onset of CML, the placebo group, imatinib alone (0.2 mg / g, daily), anti-PD-L1 antibody (0.2 mg / body, every 2 days), imatinib / anti-PD-L1 antibody The drug was divided into combination groups, and the effect was determined by comparing the absolute numbers of CML stem cells in the bone marrow and spleen 3-4 weeks after the drug.
As a result, as shown in FIG. 5, it was found that the combined use of imatinib and anti-PD-L1 antibody significantly prolonged the survival of CML mice as compared with both imatinib alone and anti-PD-L1 antibody alone. Therefore, it was found that the combined use of an immune checkpoint inhibitor and a tyrosine kinase inhibitor has a remarkably excellent therapeutic effect on leukemia, particularly tyrosine kinase resistant leukemia.
In addition, as shown in FIG. 6, the number of CML stem cells / progenitor cells in the bone marrow after imatinib and anti-PD-L1 antibody combination therapy was dramatically reduced as compared with the imatinib alone administration group. Therefore, it was found that the combined use of an immune checkpoint inhibitor and a tyrosine kinase inhibitor dramatically reduced stage G0 leukemic stem cells.

Claims (5)

A leukemia treatment drug that is a combination of an immune checkpoint inhibitor and a tyrosine kinase inhibitor. The leukemia therapeutic agent according to claim 1, wherein the leukemia therapeutic agent is a leukemia therapeutic agent that reduces G0 phase leukemia stem cells. The leukemia therapeutic agent according to claim 1 or 2, wherein the immune checkpoint inhibitor is an anti-PD-L1 antibody, an anti-PD-1 antibody, or an anti-CTLA-4 antibody. Tyrosine kinase inhibitors are imatinib, nilotinib, ibrutinib, ponatinib, bostinib, dasatinib, osimertinib, axitinib, bandetanib, basopanib, gefitinib, dacomitinib, nintedanib, kizailtinib The leukemia therapeutic agent according to any one of claims 1 to 3, which is a component selected from the salt of. The leukemia therapeutic agent according to any one of claims 1 to 4, which is a leukemia therapeutic agent composition containing an immune checkpoint inhibitor and a tyrosine kinase inhibitor.

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